Material bending machine with roll bar



Nov. 21, 1961 Filed Oct. 29, 1959 G. F. HANSEN MATERIAL BENDING MACHINEWITH ROLL BAR 3 Sheets-Sheet 1 N Geo/ye [Ta/Z5672,

Nov. 21, 1961 cs. F. HANSEN 3,009,201

MATERIAL BENDING MACHINE WITH ROLL BAR I Filed Oct. 29, 1959 3Sheets-Sheet 2 Nov. 21, 1961 G. F. HANSEN MATERIAL BENDING MACHINE WITHROLL BAR Filed Oct. 29, 1959 if 75 16 p 45 62 4 7i 6 47\Q o 5 7 1 '75 50@5 W I ix a 5 Sheet-Sheet S IN V EN TOR. flea/g6 Uawen, BY

MATERIAL BENDING MACHNE WI] H ROLL BAR George F. Hansen, Elgin, Ill.,assignor to Fawn Fabricators Inc., Elgin, Ill., a corporation ofIllinois Filed Oct. 29, 1959, Ser. No. 849,678 Claims. (CI. 18-19) Theinvention relates to material bending apparatus and has reference moreparticularly to apparatus for bending thermoplastic sheet material overrounded and formed edges of backing members and wherein the arcuatecontour of the bend may vary in r-adii over a considerable range.

The bending machine of the invention is ruggedly constructed accordingto all engineering requirements to thereby permit day-in and day-outrepetitive use. Another object of the invention resides in the provisionof a novel and improved bending machine which will perform its bendingfunctions in a single and continuous operation so that preforming of thesheet material is eliminated.

Another object of the invention is to provide a bending machine of thetype described which will employ one or more power cylinders foractuating a presser foot for applying pressure to the plastic materialadjacent the edge to be bent, the said power cylinder thereafteractuating a roll bar device for effecting the bending of the materialaround the formed and arcuate edge of the backing member.

A further object is to provide a machine for bending thermoplasticmaterial which will incorporate an improved movable roll bar device forbending the material in a manner as described and wherein said roll bardevice will be constructed so as to operate in such a manner as tocompensate for varying and different thicknesses of said material andfor variations in the size of the formed and arcuate edge of the backingmember.

Another and more specific object of the invention resides in theprovision of a new and novel roll bar device which will bend the edge ofthe plastic material around and under the formed and arcuate edgeportion of the backing member, thereby effecting a one hundred andeighty degree wrap around bend in the material.

Another object is to provide a bending machine which will be eflicientin operation, relatively simple in construction and which can beeconomically manufactured.

With these and other objects in view, the invention may consist ofcertain novel features of construction and operation, as will be morefully described and particularly pointed out in the specification,drawings and claims appended hereto.

In the drawings which illustrate an embodiment of the device and whereinlike reference characters are used to designate like parts- FIGURE 1 isa front elevational view illustrating the improved material bendingmachine of the invention;

FIGURE 2 is an elevational view of the left end of the bending machineas shown in FIGURE 1;

FIGURE 3 is a fragmentary vertical sectional view showing the presserfoot in pressure contact with a thermoplastic sheet and illustrating themode of operation of the roll bar device for bending the edge of thesheet; and,

FIGURE 4 is a fragmentary vertical sectional view similar to FIGURE 3but illustrating a full wrap around position of the roll bar device;

Referring more particularly to the drawings which disclose a preferredembodiment of the invention, the numeral 10, FIGURE 1, indicates thesupporting frame of the machine and which essentially consists of sideframe supports 11 and 12, -a longitudinal top frame member "14 and alongitudinal intermediate frame member 15.

The top and intermediate frame members extend horithe intermediate framemember 15.

3,009,201 Patented Nov. 21,, 1961 zontally and connect with the sideframe supports. The frame of the present machine also includes ahorizontally extending table 16, FIGURE 2, which also extends betweenand connects with the side frame supports 11 and 12. The table 16 islocated below the intermediate frame member 15 having a positionapproximately midway of the frame and the said table provides a flatsurface for supporting the backing member 17 and the material 18 to beprocessed. Along the rear edge of the table 16 there is located a stopmember such as 20 and the said table along its front edge is providedwith a forwardly extending flange 21. The flange 21 receives andpositions the formed and arcuate edge portion 22 of the backing member17. The thermoplastic sheet material 18 is adapted to be adhesivelysecured to the backing member 17, and the numeral 23 indicates the edgeof the thermoplastic sheet which is to be bent by the machine of theinvention to form a full wrap around covering 24, FIGURE 4, for theformed and arcuate edge portion 22.

The presser foot and roll bar device which constitute the main elementsof the present bending apparatus are suspended from an upper channelmember 25 which extends horizontally between and is supported by theside frame supports 11 and 12. The upper channel member 25 at itsrespective ends is mounted on the side frame supports in a mannerpermitting movement vertically to and from an operative and inoperativeposition. For this purpose the ends of the upper channel member areprovided with mounting plates 26 and 27, FIGURE 1, respectively, eachplate carrying a plurality of rollers 28. Plate 26 is fixed to the lefthand end of the member 25 and is located adjacent the outside surface ofthe side frame support 11. The rollers 28 are positioned to have rollingcontact with the front and rear edges of the frame support. In a similarmanner plate 27 is fixed to the right hand end of the upper channelmember 25 and said plate is adjacent the outside surface of the sideframe support 12, having the rollers 28 which roll on the front and rearedges of the said support. Accordingly, the upper channel member isadapted to reciprocate on the side frame supports from an upperinoperative position as shown in FIGURE 3, to a lower operative positionas shown in FIGURE 4.

The reciprocating movement of the member 25 is effected by powercylinders 30 which are supported by the top and intermediate framemembers. One or more power cylinders may be located on respective sidesof the center of the machine, depending on the size of the machine andthe power required for the bending operation. Bracket 31, as best shownin FIGURE 2, assists in mounting the top end of each power cylinder tothe top frame member 14, whereas bracket 32 assists in supporting thelower end of the power cylinders from The piston rod such as 33 of eachpower cylinder is suitably connected to the clevis 34 which, in turn, ispivoted to bracket 35 bolted to the top flange of the upper channelmember 25. When the power cylinders 30* are energized to move theirpiston in a downward direction, their respective piston rods 33 move thechannel member 25 in a downward direction, thus moving the member fromits inoperative position as shown in FIGURE 3, to its operative positionas shown in FIGURE 4.

A plurality of push rods are suspended by the upper channel member, thesaid rods being designated by the numeral 36. Each push rod extendsthrough the flanges of the said upper member. For example, as best shownin FIGURE 3, the push rods 36 extend through the lower flange 37 of themember 25 and through the upper flange 38 of the upper channel member.The push rods 36 also extend above their bearing 41 to receive a pin 42which determines the normal position of the push rods. The said normalposition of each push rod is yieldingly maintained by the tension spring43, the said spring being helical and having a surrounding relation withits respective push rod. It will be understood that the top end of thecoil spring 43 is adapted to have contact with the undersurface of topflange 38, whereas the lower end of each spring 43 is adapted to contacta pin 44 carried by the push rod and normally located immediately abovethe lower flange 37. The expanded tension of spring 43 is thus appliedto its push rod through the pin 44, and accordingly, each push rod isnormally urged in a downward direction. The pins 42 and 44 act as stops,since they function to limit movement of the push rods in a directiondownwardly as yieldingly urged by the respective coil springs.

A lower channel member indicated by numeral 45 is suitably fixed to thelower depending end of the push rods 36. Again, referring to FIGURE 3,it will be seen that each push rod 36 extends through the top flange 46of the channel member 45 and has abutting contact with the lower flange47. A securing screw may be employed to connect each push rod to theflange 47, or the said push rods may be welded to said flange. In eithercase the lower channel member 45 is fixedly secured in a predeterminedposition to the push rods and reciprocating movement of the said rods ascaused by movement of the upper channel member will, accordingly, beimparted to the lower channel member. A shoe plate such as 48 may besecured to the undersurface of the flange 47 as by the screw and wingnut 49 and a resilient presser foot 50, preferably formed of rubber, issuitably secured to the undersurface of the shoe plate. It is desirableto form the presser foot 50 of rubber or other suitable resilientmaterial, since the presser foot is adapted to contact the surface ofthe thermoplastic sheet material 18 for applying pressure thereto so asto hold the sheet in firm and secure contact with the backing member ata location adjacent the formed and rolled edge of said member.

In accordance with the invention the roll bar device is actuated by theconjoint action of the upper channel member and the lower channelmember. The said roll bar device, generally indicated by numeral 52, issuspended from the upper channel member by the hangers 53. The upper endof each hanger is pivotally secured as at 54 to bracket 55 secured tothe top flange 38 of member 25 by the securing bolts 56. The channelmember 57 which constitutes one of the elements of the roll bar deviceprovides a top flange 58 and a lower flange 60*. Brackets 61 are securedto the top flange 58 by securing bolts such as 62, and each bracket ispivotally connected as at 63 with the lower depending end of a hanger53. The center web of the channel member-57 is provided with a pluralityof brackets 64, each bracket being secured to the channel member 57 bysecuring bolts such as 65. The arms 66 of the roll bar are pivoted at 67to the brackets 64, and thus the arms are carried by the channel member57 in a manner to permit rotation of the arms about pivot axis 67. Bymeans of the flat tensioning springs 68, the arms are yieldingly biasedin a clockwise direction, and the numeral 70 indicates an adjustablestop so that the arms 66 are normally held in a predetermined positionby the tension exerted by the flat springs 68. It is understood that aplurality of arms 66 will be carried by the channel member 57 and thesaid arms are suitably connected by a shaft such as 71 which journalsthe rollers 72. The rollers 72, accordingly, extend the length of themachine from adjacent side frame 11 to adjacent side frame 12, and uponactuation of the roll bar device the rollers are caused to contact theprojecting edge 23 of the thermoplastic sheet material and effect a wraparound bend of the edge with respect to the formed and arcuate edgeportion 22.

For controlling the rolling and bending movement of the arms 66 thechannel member 57 which carries the said arms is pivotally connected tothe lower channel member 45. The said pivotal connection of channelmember 57 to channel member 45 is effected by the strap hinge 73, thesaid strap hinge having a leg 74 which is secured to the inside surfaceof flange 47 of the lower channel member 45 as by welding or otherconvenient means. The said strap hinge is also provided with a secondleg 75 which is similarly secured to the top flange 58 of the channelmember 57.

The first step in the bending operation is to heat the overhanging edge23 of the thermoplastic sheet in order to soften the same and facilitatethe bending of the overhanging edge. This heating step is accomplishedby the heaters which are suitably secured at 81 to the supporting arms82. The said arms are pivotally supported at 83 by means of one or morebrackets 84 and which are suitably secured to the underside of framemember 15. The inoperative position of the heaters 80 is shown in FIGURE2 in full lines, with the operative position of the heaters being shownin dotted lines. For swinging the supporting arms 82 so as to move theheaters to and from operative and inoperative positions, a powercylinder 85 is provided, the piston rod 86 of which is secured to theclevis 87. The clevis is, in turn, pivoted at 88 to bracket 90 suitablyfixed to its respective supporting arm 82. It is only necessary toenergize the power cylinder 85 to cause its piston rod to project,whereby the heaters 80 are moved into their operative position directlyover the projecting edge 23 of the thermoplastic sheet. To terminate theheating operation the heaters are withdrawn by a retraction of thepiston rod within the power cylinder.

During the heating operation the presser foot 50 and the roll bar device52 remain in an elevated inoperative position. However, immediatelyfollowing the heating operation the power cylinders 30 are energized tomove the channel member 25 in a downward direction. Similar movement isaccordingly etfected of the push rods 36 and the channel member 45.Eventually the resilient presser foot 50 will be caused to contact thethermoplastic sheet 18' and thereafter downward movement of channelmember 25 will produce a pivoting action of the roll bar device 52 in aclockwise direction. It will be understood that downward movement ofchannel member 25, after the presser foot 50 has contacted thethermoplastic sheet, will take place against the tension of springs 43,and, accordingly, the said springs 43 are compressed.

The pivoting action of the roll bar device as referred to will bring theroll bar 72 into contact with the projecting edge 23 and the said edgewill be rolled around the portion 22 of the backing member. A full wraparound of the projecting edge is effected as shown in FIGURE 4 by theaction of the arms 66 of the roll bar device. The channel member 57 inaddition to supporting the arms 66 has the further utility of contactingthe formed edge approximately intermediate the top and bottom surfacesand the pressure applied by the channel member 57 additionally assistsin the formation of a wrap around bend which is firmly and adhesivelysecured to the edge portion of the backing member.

When the roll bar 72 is caused to initially contact the projecting edge23 of the thermoplastic sheet, the position of the roll bar device issuch as to force the arms 66 in a clockwise direction and thus the stop70 is caused to contact the undersurface of flange 60. However, towardcompletion of the wrap around bend, the position of the roll bar devicewith respect to the formed and arcuate bend is such as to cause rotationof the arms 66 in a counterclockwise direction, at least with respect tothe channel 57. It will be observed that this is provided for by thepivotal connection of the arms 66 at 67 and by the resilient tensionwhich is applied to the arms by the flat spring 68. Accordingly, theroll bar device will automatically compensate for variations inthickness as regards the thermoplastic sheet and also variations in thesize and contour of the arcuate edge portion 22 of the backing member.Thus, during the bending operation the roll bar device will pivot as aunit with respect to channel member 45 as provided by the strap hinge 73and additionally the arms 66 will pivot with respect to their pivot axis67. Also, it will be observed that the several steps in the bendingoperation take place sequentially, since the presser foot 50 is firstcaused to contact the thermoplastic sheet, and since channel 45 isthereupon held stationary, continued downward movement of channel member25 will effect the desired pivoting action of the roll bar device. Atthe completion of the bending operation the channel member 25 is movedin an upward direction and the first result of this movement is to causepivotal movement of the roll bar device in a counterclockwise directionabout axis 73. Continued upward movement of channel '25 will eventuallywithdraw the presser foot 50, whereupon the parts will be again locatedin their elevated inoperative position as shown in FIG- URE 2.

This invention is not to be limited to or by details of construction ofthe particular embodiment thereof illustrated by the drawings, asvarious other forms of the device will, of course, be apparent to thoseskilled in the art without departing from the spirit of the invention orthe scope of the claims.

What is claimed is:

1. In material bending apparatus, in combination, supporting framestructure providing a Work supporting member, a presser foot mounted formovement to and from the work supporting member, a roll bar deviceincluding a supporting member, a roll bar and arms pivotally connectingthe roll bar with the supporting member, resilient means fixed to thesupporting member and engaging the anms for yieldingly maintaining thesaid arms and roll bar in a predetermined position with relation to thesupporting member, hinge means pivotally connecting the supportingmember with the presser foot, and power means for sequentially effectingdown-ward movement of the presser foot for contact with a workpiece onthe work supporting member and pivotal movement of the roll bar deviceto cause the roll bar to perform a bending operation, and which willthereafter sequentially eflt'ect pivotal movement of the roll bar devicein a reverse direction followed by upward movement of the presser footto its initial location, said resilient means automatically compensatingfor variations in the size and thickness of the workpiece as encounteredby the roll bar during the bending operation.

2. In material bending apparatus, in combination, supporting framestructure providing a work supporting member, an upper channel membermounted on said frame structure for reciprocating movement toward andfrom the work supporting member, a plurality of push rods suspended fromthe upper channel member, resilient means associated with the member andwith each push rod for yieldingly maintaining the push rods in maximumextended position, a lower channel member fixed to the extended ends ofthe push rods, a presser foot provided by the lower channel member, aroll bar device including a supporting member and a roll bar having apivotal connection with the supporting member, hinge means pivotallyconnecting the supporting member with the lower channel member,connections between the upper channel member and the supporting memberof the roll bar device, and power means for reciprocating the upperchannel member.

3. In material bending. apparatus as defined by claim 2, additionallyincluding a plurality of arms for pivotally connecting the roll bar tothe supporting member, and resilient means fixed to the supportingmember and contacting the arms for yieldingly biasing the arms into apredetermined position.

4. In material bending apparatus, in combination, supporting framestructure providing a work supporting member, an upper channel membermounted on said frame structure for reciprocating movement toward andfrom the work supporting member, a plurality of push rods suspended fromthe upper channel member and extending a distance below the said member,resilient means associated with the member and with each push rod foryieldingly maintaining the push rods in maximum extended position, alower channel member fixed to the extended ends of the push rods, aresilient presser foot provided by the lower channel member, a roll bardevice including a supporting member, a roll bar and a plurality of armsfor pivotally connecting the roll bar with the supporting member, hingemeans pivotally connecting the supporting member with the lower channelmember, hangers having pivotal connection at respective ends with theupper channel member and the supporting member, and power means forreciprocating the upper channel member.

5. In material bending apparatus as defined by claim 4, additionallyincluding resilient means fixed to the supporting member and contactingthe arms for yieldingly biasing the arms into a predetermined position,and an adjustable stop associated with the arms for adjusting saidpredetermined position.

References Cited in the file of this patent UNITED STATES PATENTS2,252,491 Cloyd Aug. 12, 1941 2,288,273 Enghauser June 30, 19422,552,616 Bath May 15, 1951 2,866,493 Kovalcik Dec. 30, 1953 2,937,689Peterson May 24, 1960

